This 3M Sanding Sponges is designed for sanding wood, paint, metal, plastic or drywall. This sponge features conventional 3M abrasives & is made with durable, flexible foam. The block shape makes it easy to hold & sands flat, contoured, or irregular surfaces. Sanding is an integral step in preparing a surface to receive a coating. For the best sanding results, sand with the grain of the surface & work through a sequence of grits, from coarse to very fine, skipping no more than one grit between each sanding step.